Writing to text files in C

main.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char* argv[]) {
    FILE* in;
    FILE* out;
    
    char buffer_in[256], buffer_out[256];
    out = fopen("point.dat", "w");
    if (out == NULL) {
        return 1;
    }
    
    snprintf(buffer_out, 256, "%d %d\n", p1.x, p1.y);
    size_t bytesWrote = fwrite(buffer_out, sizeof(char), strlen(buffer_out), out);
    fclose(out);
    
    if (bytes_wrote != strlen(buffer_out)) {
        return 1;
    }
    return 0;
}